Classifications

• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
  • F16L—PIPES; JOINTS OR FITTINGS FOR PIPES; SUPPORTS FOR PIPES, CABLES OR PROTECTIVE TUBING; MEANS FOR THERMAL INSULATION IN GENERAL
  • F16L11/00—Hoses, i.e. flexible pipes
  • F16L11/04—Hoses, i.e. flexible pipes made of rubber or flexible plastics
  • F16L11/12—Hoses, i.e. flexible pipes made of rubber or flexible plastics with arrangements for particular purposes, e.g. specially profiled, with protecting layer, heated, electrically conducting
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
  • F16L—PIPES; JOINTS OR FITTINGS FOR PIPES; SUPPORTS FOR PIPES, CABLES OR PROTECTIVE TUBING; MEANS FOR THERMAL INSULATION IN GENERAL
  • F16L11/00—Hoses, i.e. flexible pipes
  • F16L11/04—Hoses, i.e. flexible pipes made of rubber or flexible plastics
  • F16L11/08—Hoses, i.e. flexible pipes made of rubber or flexible plastics with reinforcements embedded in the wall
  • F16L11/085—Hoses, i.e. flexible pipes made of rubber or flexible plastics with reinforcements embedded in the wall comprising one or more braided layers

Definitions

• the present invention relates to the field of extensible flexible hoses, especially but not exclusively intended for use for irrigation, and more specifically relates to a new configuration for such a hose, and the relative production process.
• Flexible hoses are known for the passage of a fluid under pressure, mainly a liquid such as irrigation water, the configuration of which is such as to ensure a significant (and automatic) elongation of the hose itself when subjected to the pressure of the liquid inside it, then retreating to the original or rest size when this pressure ceases, i.e. when the tube is emptied.
• a fluid under pressure mainly a liquid such as irrigation water
• the configuration of which is such as to ensure a significant (and automatic) elongation of the hose itself when subjected to the pressure of the liquid inside it, then retreating to the original or rest size when this pressure ceases, i.e. when the tube is emptied.
• the handling of the hose when not in use is much simpler and more convenient, due to the reduced overall dimensions.
• a wire generally made of a plastic material, runs in a spiral pattern along the body of the hose (in a polymeric elastic material), and becomes extended in response to the fluid pressure, causing the elongation of the hose, while getting back to the shortened condition when the pressure ceases;
• hoses in which a layer of textile material is sandwiched between two layers of polymeric elastic material so as to form a unitary structure, the textile material being elastically extensible so as to exert a control of the hose extension similar to that of the above mentioned the spiral wire.
• This kind of hose structure is disclosed in document EP3323468, in which the above- mentioned textile layer, basically obtained by knitting, weaving or knotting, is co-extruded and welded in a sandwich between two polymeric layers.
• the extension mechanism is such as to determine an abrasive action between the inner tube and the outer layer, in the phases in which the first expands and goes to find the stop action from the outer layer.
• abrasions repeat, with the continuous use of the hose, a rapid deterioration of the hose ensues, and the same hose corns to an early breakage. Even more significant is the weakness at the connections positioned at the ends, and indispensable for use.
• the inner tube increases its diameter when the liquid under pressure passes, and, encountering the containment barrier from the textile layer, it cannot continue to expand, so that a thrust is generated in the longitudinal direction which allows it to be lengthened.
• the tube undergoes an abrupt swelling in all its extension which impacts violently at the end junction point, generating a high risk of damage.
• the material undergoes a particular stress capable of compromising the solidity of the bonds, until they deteriorate and become subject to tearing; this failure risk entails a clear limitation of the possibility of use and of maintaining the desired performance.
• the wrinkled start state of the outer layer in the hose rest condition causes, in this condition but also during the elongation phase, the possibility that the hose gets caught by protrusions present on its path or in its use environment.
• the wrinkles also cause the drawback that the hose gets soiled more easily, and is more difficult to clean, a drawback indeed also presented by other types of known extensible hoses with a non-textile exterior, due to the stickiness of the material that forms the exterior wall of the hose.
• the above-mentioned extensible hoses are generally structured so that the diameter of the passage duct is, in the working condition, more or less double than that of the rest condition.
• the diameter of the outer layer clearly corresponds to the working diameter of the inner tube, and is therefore quite big even in the rest condition. Therefore, the hose is rather cumbersome, both in the working condition and even in the rest condition.
• a particular object of the present invention is to provide a flexible extensible hose of the above-mentioned type, that takes up minimal space in the rest condition as well as in the working condition.
• Another particular object of the present invention is to provide a flexible extensible hose of the above-mentioned type, which has low tendency to get caught on external elements in the environment in which it is used.
• a further particular object of the present invention is to provide a flexible extensible hose of the above-mentioned type, which has a reduced tendency to collect and/or adsorb dirt from the environment, and in any case is easily and successfully washable.
• An even further object of the present invention is to provide a flexible extensible hose of the above-mentioned type, which can be manufactured with a single-stage productive process and thus with reduced production times and costs.
• FIG. 1 is a perspective view of a hose according to the invention, with its relative end connectors, at one of which a hand sprinkler is mounted;
• FIG. 2 is a perspective view of a hose piece according to the invention, broken so as to show its configuration, in a rest condition;
• figure 3 is a side view of a hose segment in a rest condition, with a caliper tool showing its diameter, figure 3a being an enlarged detail of the same figure 3;
• figure 4 is a side view of a hose segment in an extended or work condition, with a caliper tool showing its diameter, figure 4a being an enlarged detail of the same figure 4;
• FIG. 5 represents in a perspective view a step of the manufacturing process of the hose according to the invention in a braiding machine.
• the hose according to the invention comprises an inner tube 1 made of an elastic polymeric material, in one or more layers, obtained by extrusion, typically natural or synthetic rubber or other similar materials having suitable properties such as TPE, TPE-S, TPE-SEBS, TPE-O, PP/SEBS, PP/EPDM, silicone materials, in any case with a hardness preferably between 20 and 70 Sh A.
• the inner tube 1 is covered in a loose fashion by a tubular outer layer 2 made of textile material which, as will be better explained below, is made with a braiding process, adapted to produce an axially extensible pattern, directly around the inner tube 1 and so as to result in substantial contact, but without adhesion, to the same in the rest condition.
• the textile fibers used to braid the outer layer 2 are preferably made of polypropylene (as a non-limiting example, with a linear density of 1100 dtex and a torsion comprised between 60 and 100).
• Suitable yarns can also be polyester, polyamide, polyethylene, para-aramid fibers and other fibers which are tendentially not elastic or otherwise with negligible elasticity.
• the yarn can advantageously undergo a preventive bath to reduce its abrasiveness and therefore slow down its deterioration, for example with a coating substance such as polyurethane or other materials of similar properties and suitable for the purpose.
• the inner tube can have various dimensions, but for example it can be a tube having dimensions between 6 mm and 10 mm (typically about 8 mm) as an internal diameter, and between 8 mm and 14 mm (typically about 11 mm) as an outer diameter.
• a tube is fed along its central or longitudinal axis X to a closed braiding machine M of a known type for making tubular cords, for example with 24 spindles, which provides for the realization of the textile outer layer.
• a suitable machine can for example be a vertical rotary braider such as, among the many available on the market, the 120 Stitch model of the Italian company ETK s.r.l. (www.etkstl.it)
• the inner tube 1 is moreover kept, through suitable stretching devices, in a stretched arrangement (always obviously along the axis X) for at least a segment which comprises the braiding region, so as to cause an elongation, which can even be quantitatively small but in most cases will be advantageously between 3 and 4 times the length at rest, preferably about 3.7 times.
• This stretch corresponds to a thinning of the external diameter of about 5-6 mm (in the context of the basic dimensions indicated above), but in general, depending on the starting diameter, it will possibly oscillate between 3 mm and 10 mm.
• the stretching devices comprising in particular roller systems distributed in number, configuration and actuation parameters which vary according to the amount of the desired stretching, can be obviously devised or arranged according to technologies already in use in braiding machines.
• the textile layer in the form of an outer tubular structure 2 which remains completely loose, not adherent, with respect to the inner tube 1 and which will itself define the outer surface of the hose without further layers thereon, is therefore constructed around an inner tube thus thinned.
• an outer tubular layer 2 is made which is adapted to take on substantially the same maximum diameter (the diameter obtained with the maximally compressed or "closed" yarn pattern, i.e. with fibers as close as possible to the plane orthogonal to the central axis X) with respect to the outer diameter D1 of the inner tube at rest.
• a braiding angle a is set (i.e.
• This setup is obtained, for example, according to the embodiment shown in Figure 5, thanks to a ring arranged coaxially with the machine axis X’, which with its internal diameter clamps the bundle of wires coming from the spools at different angles and in any case greater than 20°, by forcing a homogeneous change of angle and at the same time controlling the height of the braiding region, ensuring that it remains at a certain distance - useful for avoiding mechanical interference - with respect to the device to collect the hose.
• the tubular outer layer thus created will be able to prevent the radial expansion of the inner tube beyond the diameter D1 of the rest condition, and then promote and assist its extension, with distension and opening of its pattern (yarns that become more angled with respect to the plane orthogonal to the X axis).
• This aspect will be considered in more detail hereafter, describing the working behavior of the hose.
• the inner tube 1 is no longer being stretched and elastically retracts, taking again the length and the diameter of the rest condition.
• the dynamic interaction between the inner tube and the outer layer is such as not to generate significant abrasion phenomena, as the outer layer does not lengthen sharply and macroscopically between the rest condition and that of use, indeed going to accompany and assist the longitudinal extension of the inner tube. This results in lower risks of breakage and longer duration.
• the compact configuration (both radially and axially) of the outer layer even and already in the rest condition avoids entanglement or twisting phenomena, and prevents the collection of dirt, in any favoring the easy and effective washability if the hose is used in particularly dirty environments, for example muddy environments.
• the hose according to the invention is generally non-deformable, and it does not tend to twist or to form knots.
• the passage of liquid inside is always guaranteed. No bottlenecks or obstructive folds are created when the liquid flows.
• the resistance to high pressures is high (compared to the standard of the hoses usually employed in the irrigation sector) due to the strong containment exerted by the textile pattern that covers the inner tube. Thanks to the materials used and the way in which they are combined, the hose is still very light and therefore can be easily handled even by users without particular physical strength.
• the present invention adopts a completely different nature of production technology; in the present case, in fact, there is no complex and costly line of machinery for the co extrusion of the polymeric tubes and concurrent realization of the textile layer to realize a unitary structure in which the textile layer is irreversibly sandwiched, incorporated and invisible between two polymeric layers, one of which represents the outer layer of the hose.
• the very fact that the outer layer is a polymeric one causes a rapid decay or at least an easy dirtying of this known hose, which becomes - in particular after a certain use - consequently unpleasant to the touch.
• this type of known hose is not in any case capable of ensuring the performance of the hose according to the present invention.
• the performance of the hose can clearly vary and be suitably optimized, depending on the specific working requirements. It should be noted in this regard that even with a minor stretch of the inner tube 1 in the feeding step, it will still be possible to obtain a hose which, although not reaching the mentioned high extension performance, will still be moderately extensible and always achieving at least partially, but in any case appreciably, the production and working advantages mentioned above.
• the hose In addition to irrigation, which still represents the use for which the hose according to the invention is particularly suitable, the hose can in generally be profitably used for any similar requirement of passage/distribution of liquids but also and even more generally of fluids such as compressed air.

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• Engineering & Computer Science (AREA)
• General Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Rigid Pipes And Flexible Pipes (AREA)
• Laminated Bodies (AREA)

Priority Applications (12)

Applications Claiming Priority (2)

Related Child Applications (2)

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• 2019
  • 2019-09-27 JP JP2021512451A patent/JP7434290B2/ja active Active
  • 2019-09-27 ES ES19790072T patent/ES2929213T3/es active Active
  • 2019-09-27 MA MA53731A patent/MA53731B1/fr unknown
  • 2019-09-27 EP EP19790072.3A patent/EP3857107B1/en active Active
  • 2019-09-27 WO PCT/IB2019/058219 patent/WO2020065601A1/en unknown
  • 2019-09-27 CA CA3111676A patent/CA3111676A1/en active Pending
  • 2019-09-27 HU HUE19790072A patent/HUE060406T2/hu unknown
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  • 2019-09-27 EP EP22188339.0A patent/EP4105532A1/en active Pending
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  • 2019-09-27 CN CN201980063838.6A patent/CN112771298B/zh active Active
  • 2019-09-27 US US17/273,992 patent/US11486518B2/en active Active
• 2021
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• 2022
  • 2022-09-23 US US17/934,720 patent/US11767933B2/en active Active

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